The Mayor of London has warned it could take a generation to turn the tide of violent crime after four fatal stabbings in less than a week.

Speaking on Radio 4's Today programme on Monday, Sadiq Khan said that the success in Glasgow at stopping bloodshed showed that similar efforts in London would take time.

He has adopted the public health approach used by authorities in the Scottish city, where bodies such as health, education, social services, housing and police worked together to stop young people becoming involved in crime.

The mayor said: "It will take some time. I know that because of the lessons we've learnt from places like Glasgow, where it took them some time to turn this round.

"To really make significant progress can take up to 10 years, a generation.

"They saw in Scotland what we are seeing in London, which is children in primary schools thinking not only is it OK to carry a knife, but it gives them a sense of belonging in joining a criminal gang and it makes them feel safer and they see nothing wrong in getting involved in this sort of behaviour."

Concerns over violent crime have been renewed after four murders in five days in the capital.

Scotland Yard said 17-year-old Malcolm Mide-Madariola was fatally knifed on Friday outside Clapham South Tube station, south London, near where he studied.

On Monday detectives arrested another teenager, also aged 17, on suspicion of his murder, and appealed for witnesses to come forward.

The boy, from Peckham, south-east London, was attacked less than a day after 15-year-old Jay Hughes was killed in Bellingham, south-east London, by a stab wound to the heart.

Meanwhile, a man believed to be aged 22 was fatally stabbed in Samos Road, Anerley, south London, at about 12.30pm on Sunday.

And Rocky Djelal, 38, was fatally knifed at about lunchtime on Halloween as children played nearby in Southwark Park, Rotherhithe, south-east London.

Metropolitan Police Commander Stuart Cundy said on Monday that it had been a "terrible" few days in the capital as he announced that hundreds more police officers would be on duty.

He said: "Tragically, we have had four murders since Wednesday of last week, none of them are connected.

"That's four families, four groups of friends and acquaintances, who have all been tragically affected by this senseless violence."

The Met's violent crime taskforce has carried out more than 21,000 weapons searches since April, seizing hundreds of guns and knives.

There have now been 116 homicides in London so far this year.

Home Office minister Victoria Atkins blamed a change in the nature of crime, rather than cuts in police numbers, for the recent spike in gang-related violence in London and other cities.

She told Today that an intensive Government review had shown that "the claim about police numbers isn't supported by the evidence of previous spikes in serious violence".

Ms Atkins said: "We are all, I think, realising that the nature of crime is changing.

"Of course, violence has been around as long as human beings have been around, but we have seen - and the Met Commissioner herself has talked about - the ways in which gangs are much more ruthless than they used to be.

"The levels of violence which doctors are now seeing in A&Es show that incidents which before perhaps wouldn't have resulted in fatalities now are resulting in fatalities.

"We and the police and others have to face up to the reality that criminals are changing their crime types and we have to be able to tackle that."

However Mr Khan told the broadcaster: "The Home Office's own officials, in a leaked document, said there is a link between police officer numbers going down and crime going up.

"The cross-party Home Affairs Select Committee published a scathing report two weeks ago talking about the link between a cut in police resources and the increase in crime.

"The most senior police officers in the country have said it's naive to think there's not a link between cutting police numbers and an increase in violent crime."

Asked about Mr Khan's suggestion that it could take a generation to turn the tide on violence, the Prime Minister's official spokesman said: "It's something we need to be focused on finding solutions to from today."